Sometimes Tasker variables are not loaded to the watch. I can see the correct actual value in the phone app, it shoes me a correct preview, I'm pressing "sent to watch", the watch face gets updated but with an old variable. Sending variable from Tasker one more time forces updating it on the watch.
So it looks as if the phone WatchMaker had two separate instances of the same Tasker var: one for sending to phone and another one for building preview on the phone. And this two instances can differ.
This happens on Android Wear 2.0, it was fine on 1.5.